The 2023 dengue outbreak in Bangladesh is the worst recorded, with 277,801 cases and 1,393 deaths as of November 3, 2023. The outbreak has spread beyond Dhaka, with 52% of cases occurring outside the capital. The male-to-female ratio was 3:2, and the highest frequency of cases was among individuals aged 19–29 years (28.7%). The overall case fatality rate (CFR) was 0.5%, with the highest CFR among children aged 10–10 years (12%). Fever (99%) and joint pain (86%) were the most common symptoms. Multivariable logistic regression analysis revealed significantly higher odds of fatalities, cases, and hospitalizations during the 2023 outbreak compared to previous outbreaks (2008–2022). The outbreak started earlier and spread more rapidly, with Chattogram and Barisal divisions becoming new hotspots. Climate change, urbanization, and environmental factors are contributing to the increased prevalence and severity of dengue outbreaks in Bangladesh. This study provides early epidemiological and clinical insights into the 2023 dengue outbreak, which will aid future research and public health interventions.The 2023 dengue outbreak in Bangladesh is the worst recorded, with 277,801 cases and 1,393 deaths as of November 3, 2023. The outbreak has spread beyond Dhaka, with 52% of cases occurring outside the capital. The male-to-female ratio was 3:2, and the highest frequency of cases was among individuals aged 19–29 years (28.7%). The overall case fatality rate (CFR) was 0.5%, with the highest CFR among children aged 10–10 years (12%). Fever (99%) and joint pain (86%) were the most common symptoms. Multivariable logistic regression analysis revealed significantly higher odds of fatalities, cases, and hospitalizations during the 2023 outbreak compared to previous outbreaks (2008–2022). The outbreak started earlier and spread more rapidly, with Chattogram and Barisal divisions becoming new hotspots. Climate change, urbanization, and environmental factors are contributing to the increased prevalence and severity of dengue outbreaks in Bangladesh. This study provides early epidemiological and clinical insights into the 2023 dengue outbreak, which will aid future research and public health interventions.